There is a comprehensive account of some aspects of pollinator conservation
in the recent issues of BEE WORLD (Volume 72: 1991), mostly about Europe.
Corbet et al. Bee World 72(2):47-59
Osborne et al. Bee World 72(3):99-116
Especially relevant to the NW USA is the paper by Robinson and Johansen
(1978) in Melanderia 30:9-57 "Effect of control chemicals for Douglas-fir
tussock moth, Orgyia pseudotsugata (McDunnough) on forest pollination
(Lepidoptera:Lymantriidae)"
Data on the demise of pollinator populations is given in several papers
from various parts of the world, most having to do with bees. I will be happy
to provide anyone interested with a bibliography (albeit incomplete) by
regular mail.